Authentication encryption based on authentication code with secrecy

The idea of authentication encryption cryptosystem is proposed. This cryptosystem is a modification of an authentication code with secrecy considered in previous papers of the author and based on Reed–Solomon error-correcting code. The essence of the modification is to use a non-repeating initialization vector and derivative key for encryption of each message. Estimations of cryptosystem security as an authentication code with secrecy at a one-time usage of the key are received: the encryption security is estimated by proximity to perfect encryption, and the authentication security — by probabilities of imitation and substitution success. Considerations for selection of parameters and estimation of cryptosystem security to chosen plaintext attacks at multiple usage of the key as well as distinction attacks are provided.